Google Earth Plug-in: The graduation tower of Bad Koesel

A graduation tower (often falsely called saltworks) consists of a wooden frame, which is filled with brushwood bundles (predominant black thorn). It serves grading, i.e. increasing the salt amount of a brine. By letting the brine the graduation tower run down, wind and sun contribute to evaporating the water existing in the brine. At the same time impurities of the brine (e.g. lime or gypsum) in the brushwood sit down off and form the grey-brown thorn stone. In this way one saved simmering costs in earlier times during the salt producing and increased the quality of the salt. Today graduation towers serve mostly for short waking (by inhalation of salty air). With the first steam power plants graduation tower served the removal of the surplus process heat from the condenser. Later took over more efficient cooling towers this task. The graduation tower in bad Nauheim belongs to the oldest in Germany. The most highly concentrated brine is won with 27% of salt in the Thuringian bad Salzungen.